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Chusyd DE, Nagy TR, Golzarri-Arroyo L, Dickinson SL, Speakman JR, Hambly C, Johnson MS, Allison DB, Brown JL. Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant ( Elephas maximus). J Exp Biol 2021; 224:224/2/jeb219543. [PMID: 33500325 DOI: 10.1242/jeb.219543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 11/24/2020] [Indexed: 11/20/2022]
Abstract
Many captive Asian elephant populations are not self-sustaining, possibly due in part to obesity-related health and reproductive issues. This study investigated relationships between estimated body composition and metabolic function, inflammatory markers, ovarian activity (females only) and physical activity levels in 44 Asian elephants (n=35 females, n=9 males). Deuterium dilution was used to measure total body water from which fat mass (FM) and fat-free mass (FFM) could be derived to estimate body composition. Serum was analyzed for progestagens and estradiol (females only), deuterium, glucose, insulin and amyloid A. Physical activity was assessed by an accelerometer placed on the elephant's front leg for at least 2 days. Relative fat mass (RFM) - the amount of fat relative to body mass - was calculated to take differences in body size between elephants into consideration. Body fat percentage ranged from 2.01% to 24.59%. Male elephants were heavier (P=0.043), with more FFM (P=0.049), but not FM (P>0.999), than females. For all elephants, estimated RFM (r=0.45, P=0.004) was positively correlated with insulin. Distance walked was negatively correlated with age (r=-0.46, P=0.007). When adjusted for FFM and age (P<0.001), non-cycling females had less fat compared with cycling females, such that for every 100 kg increase in FM, the odds of cycling were 3 times higher (P<0.001). More work is needed to determine what an unhealthy amount of fat is for elephants; however, our results suggest higher adiposity may contribute to metabolic perturbations.
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Affiliation(s)
- Daniella E Chusyd
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA .,Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA.,Department of Epidemiology and Biostatistics, Indiana University-Bloomington, Bloomington, IN 47405, USA
| | - Tim R Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA.,Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA.,Nathan Shock Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lilian Golzarri-Arroyo
- Department of Epidemiology and Biostatistics, Indiana University-Bloomington, Bloomington, IN 47405, USA
| | - Stephanie L Dickinson
- Department of Epidemiology and Biostatistics, Indiana University-Bloomington, Bloomington, IN 47405, USA
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3FX, UK.,Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Catherine Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3FX, UK
| | - Maria S Johnson
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - David B Allison
- Department of Epidemiology and Biostatistics, Indiana University-Bloomington, Bloomington, IN 47405, USA
| | - Janine L Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
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Pontzer H, Rimbach R, Paltan J, Ivory EL, Kendall CJ. Air temperature and diet influence body composition and water turnover in zoo-living African elephants ( Loxodonta africana). ROYAL SOCIETY OPEN SCIENCE 2020; 7:201155. [PMID: 33391799 PMCID: PMC7735349 DOI: 10.1098/rsos.201155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
African elephants, the largest land animal, face particular physiological challenges in captivity and the wild. Captive elephants can become over- or under-conditioned with inadequate exercise and diet management. Few studies have quantified body composition or water turnover in elephants, and none to date have examined longitudinal responses to changes in diet or air temperature. Using the stable isotope deuterium oxide (2H2O), we investigated changes in body mass, estimated fat-free mass (FFM, including fat-free gut content) and body fat in response to a multi-year intervention that reduced dietary energy density for adult African elephants housed at the North Carolina Zoo. We also examined the relationship between air temperature and water turnover. Deuterium dilution and depletion rates were assayed via blood samples and used to calculate body composition and water turnover in two male and three female African elephants at six intervals over a 3-year period. Within the first year after the dietary intervention, there was an increase in overall body mass, a reduction in body fat percentage and an increase in FFM. However, final values of both body fat percentage and FFM were similar to initial values. Water turnover (males: 359 ± 9 l d-1; females: 241 ± 28 l d-1) was consistent with the allometric scaling of water use in other terrestrial mammals. Water turnover increased with outdoor air temperature. Our study highlights the physiological water dependence of elephants and shows that individuals have to drink every 2-3 days to avoid critical water loss of approximately 10% body mass in hot conditions.
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Affiliation(s)
- Herman Pontzer
- Evolutionary Anthropology, Duke University, Durham, NC, USA
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Rebecca Rimbach
- Evolutionary Anthropology, Duke University, Durham, NC, USA
- School of Animal, Plant & Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jenny Paltan
- Department of Anthropology, Hunter College, New York, NY, USA
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